SOLUTION: I have been at this math problem for quiet a while now. I would really like it if you can help me out. The answer may be so easy to get, but I just can't figure it out. Please help

Question 179512: I have been at this math problem for quiet a while now. I would really like it if you can help me out. The answer may be so easy to get, but I just can't figure it out. Please help.
The word problem is as followed:
Mr. X invested an amount for 7% and twice that amount for 8%. At the end of the year the income was $11500. What was the amount invested at 7%? amount invested at 8%?

Thanks so much .. your help is greatly appreciated!

Found 2 solutions by stanbon, ankor@dixie-net.com:
Answer by stanbon(75887) (Show Source): You can put this solution on YOUR website!
Mr. X invested an amount for 7% and twice that amount for 8%. At the end of the year the income was $11500. What was the amount invested at 7%? amount invested at 8%?
-------------------
Equation:
interest + interest = 11500
0.07x + 0.08(2x) = 11500
---------
Multiply thru by 100 to get:
7x + 16x = 1,150,000
23x = 1,150,000
x = $50,000 (amt. invested at 7%)
2x = $100,000 (amt. invested at 8%)
========================================
Cheers,
Stan H.

Answer by ankor@dixie-net.com(22740) (Show Source): You can put this solution on YOUR website!
Mr. X invested an amount for 7% and twice that amount for 8%. At the end of the
year the income was $11500. What was the amount invested at 7%? amount invested
at 8%?
:
let x = amt invested at 7%
then
2x = amt invested at 8%
;
.07x + .08(2x) = 11500
.07x + .16x = 11500
.23x = 11500
x =
x = $50,000 invested at 7%
and, obviously, $100,000 invested at 8%
;
;
Check by finding the interest of each
.07 * 50000 = 3500
.08 * 100000= 8000
-------------------
for a total = 11500

RELATED QUESTIONS
I am stumped! I have been at this math problem for what seems like hours. I would really... (answered by gonzo,Mathtut)
Hi, I'm taking an online college algebra class but can't quite recall all the review... (answered by stanbon)
OFF TOPIC QUESTION! SORRY! I'm really sorry to be asking this here as I know that it... (answered by scott8148)
Write one thousand, five hundred six and three tenths as a decimal. I have been... (answered by checkley77)
Hi, I'm new here and hope this is the right topic for my question(s)... I have some... (answered by ankor@dixie-net.com)
I have been working on this math problem for awhile now and I can't seem to figure it... (answered by jojo14344)
I have been struggling with this problem for a while now and I was wondering if anyone... (answered by stanbon,swooshfloop)
This may seem like a crazy question, but every book I have consulted gives a vague... (answered by shree840,richard1234)
my math teacher is literally horrible at teaching and every year 75% of his class fails... (answered by rodriguezh2)